Metal oxide modified fiber material as well as preparation method and application thereof
By preparing metal oxide-modified fiber materials combining xWO3@SiO2 nanofibers with polyvinylidene fluoride-hexafluoropropylene copolymer, the problems of flammability, volatility, and lithium dendrite growth in lithium battery liquid electrolytes were solved, achieving a solid electrolyte material with high energy density and long lifespan.
Patent Information
- Application Number
- CN202511023221.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-11-25
AI Technical Summary
Existing lithium batteries use liquid electrolytes that are flammable and volatile, and lithium dendrite growth affects battery energy density. Traditional solid electrolyte materials also exhibit uneven lithium-ion conduction, which affects ion transport.
xWO3@SiO2 nanofibers were prepared by electrospinning and combined with polyvinylidene fluoride-hexafluoropropylene copolymer and lithium bis(fluorosulfonyl)imide salt to form a metal oxide modified fiber material, which serves as the electrolyte for the battery. Tungsten oxide promotes lithium salt dissociation and lithium ion transport.
It significantly improves the battery's long-cycle performance, enhances battery stability and energy density, extends battery life, and solves the safety and conduction uniformity issues of liquid electrolytes.
Smart Images
Figure CN121006003A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of nanomaterials and solid-state electrolytes, and in particular to a metal oxide modified fiber material and a preparation method and application thereof. BACKGROUND
[0002] With the background of sustainable development worldwide, lithium batteries gradually become the driving force for energy development in contemporary society due to their efficient, environmentally friendly energy storage and conversion. Since the emergence of lithium batteries in the early 1980s, they have expanded from the laboratory to many fields in today's society, such as electric vehicles, mobile devices, and renewable energy, and have become a key component of the energy system. In recent years, electric vehicles and energy storage systems have increasingly urgent demands for high energy density, high safety performance, and long-term operation of batteries, and the development of liquid electrolyte lithium ion batteries is facing a bottleneck. The organic liquid used in traditional batteries is volatile and flammable, and can easily cause fires under high temperature, overcharge, or mechanical damage, which becomes a factor restricting safety performance. Solid-state electrolyte battery materials replace liquid electrolyte with non-flammable solid materials, which can fundamentally solve the problem. In addition, the high mechanical strength of solid-state electrolyte can inhibit the growth of lithium dendrites, greatly improve the energy density of the battery, and achieve further breakthroughs in energy density.
[0003] Polyethylene oxide-based electrolytes exhibit a semi-crystalline state at room temperature, and the conduction of lithium ions depends on the amorphous segment movement, so this uneven distribution will affect the obstruction of ion transmission. On this basis, polyvinylidene fluoride-hexafluoropropylene copolymer as a new type of solid-state polymer electrolyte material has received attention due to its excellent performance. Silicon dioxide nanofibers in inorganic fillers have excellent thermal stability, and tungsten oxide can promote the dissociation of lithium salt. The interaction between tungsten oxide and polyvinylidene fluoride-hexafluoropropylene copolymer provides a fast transmission channel for lithium ions. To further optimize the mechanical properties, molecular dynamics models and in-situ characterization techniques can be combined to reveal the interfacial interaction between the filler and the polymer substrate, providing stronger support for the development of solid-state electrolytes. SUMMARY
[0004] In order to overcome the deficiencies of the background art, the present application provides a metal oxide modified fiber material and a preparation method and application thereof, which mainly solve the problem of insufficient cycle performance of the current electrolyte.
[0005] The technical scheme of the present application is,
[0006] A preparation method of a metal oxide modified fiber material, comprising the following steps,
[0007] Step one, stirring tetraethyl orthosilicate, ethanol, hydrochloric acid and tungsten chloride until the solute is completely dissolved to form a mixed solution A;
[0008] Step two, polyvinylpyrrolidone is dissolved in N,N-dimethylformamide and dimethyl sulfide to obtain B mixed solution;
[0009] Step three, stirring the mixed solution of step one and step two;
[0010] Step four, electrospinning the mixed solution of step three to form xWO3@SiO2 nanofiber;
[0011] Step five, polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and lithium bisfluorosulfonylimide (LiFSI) are dissolved in N-methyl pyrrolidone (NMP) to form a homogeneous solution (PL), and then added to the mixed suspension after magnetic stirring to form a casting mold. The thickness is scraped with a doctor blade and dried.
[0012] The tetraethyl orthosilicate: ethanol: hydrochloric acid: tungsten chloride in step one is 2.6g: 0.75g: 0.5g: x g, where x = 0.3, 0.5 or 0.7.
[0013] The polyvinylpyrrolidone in step two accounts for 10wt% of the mixed solution.
[0014] The electrospinning voltage in step four is 15kV, the feeding rate is controlled at 0.6mL h -1 , the distance between the syringe needle and the collector is 15cm, and the rotation speed of the collector is set to 600rpm.
[0015] The ambient temperature in step four is room temperature, and the humidity is 30%.
[0016] The material used in step four needs to be dried in a vacuum drying oven at 60°C for 12h.
[0017] After drying the nanofiber in step four, it is calcined in a muffle furnace at 650°C for 2h to obtain the product.
[0018] In step five, 3wt.%, 5wt.%, 7wt.% or 10wt.% of xWO3@SiO2 nanofiber is added.
[0019] In step six, it is cast on a polytetrafluoroethylene substrate.
[0020] The thickness scraped in step six is 500μm.
[0021] Drying in step six requires drying in a vacuum oven at 80°C for 24h.
[0022] After drying and peeling in step six, it needs to be transferred to a vacuum drying oven for standby.
[0023] A metal oxide modified fiber material, comprising a carrier and a core, the core being tungsten oxide metal particles for promoting lithium salt dissociation, the carrier being silica nanofibers.
[0024] A metal oxide modified fiber material is prepared by the preparation method of the metal oxide modified fiber material.
[0025] Application of the metal oxide modified fiber material as an electrolyte of a battery.
[0026] The present application has the beneficial effects that the present application provides a metal oxide modified fiber material, a preparation method and application thereof, the method is simple, efficient and low in cost, the prepared solid-state electrolyte is high in stability, and the long cycle performance of a battery is significantly improved, which provides an important foundation for optimizing polyvinylidene fluoride-hexafluoropropylene copolymer-based electrolyte and developing high-performance full solid-state lithium ion batteries. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 X-ray diffraction pattern of xWO3@SiO2 described in embodiments 1-4 of the present application.
[0028] Figure 2 Image of xWO3@SiO2 described in embodiments 2, 3 and 4 under a scanning electron microscope.
[0029] Figure 3 Image of different xWO3@SiO2 addition amounts under a scanning electron microscope in embodiments 6-9.
[0030] Figure 4 Stress-strain curve in embodiments 5 and 7.
[0031] Figure 5 Constant current cycle curve of embodiments 5 and 7 in Li||embodiment 5||Li and Li||embodiment 7||Li batteries at 0.2 mA cm -2
[0032] Figure 6 Lithium metal performance of embodiments 5 and 7 after cycling under a scanning electron microscope. DETAILED DESCRIPTION
[0033] The present application will be further described below with reference to the accompanying drawings. A preparation method of a metal oxide modified fiber material comprises the following steps,
[0034] Step one, stirring tetraethyl orthosilicate, ethanol, hydrochloric acid and tungsten chloride until the solute is completely dissolved to form a mixed solution A;
[0035] Step two, polyvinylpyrrolidone is dissolved in N,N-dimethylformamide and dimethyl sulfide to obtain B mixed solution;
[0036] Step three, stirring the mixed solution of step one and step two;
[0037] Step four, electrospinning the mixed solution of step three to form xWO3@SiO2 nanofiber;
[0038] Step five, polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and lithium bisfluorosulfonylimide (LiFSI) are dissolved in N-methylpyrrolidone (NMP) to form a homogeneous solution (PL), and then added to the mixed suspension after magnetic stirring to form a casting mold. The thickness is scraped with a doctor blade and dried.
[0039] The tetraethyl orthosilicate: ethanol: hydrochloric acid: tungsten chloride in step one is 2.6g: 0.75g: 0.5g: x g, where x = 0.3, 0.5 or 0.7.
[0040] The polyvinylpyrrolidone in step two accounts for 10wt% of the mixed solution.
[0041] The electrospinning voltage in step four is 15kV, the feeding rate is controlled at 0.6mL h -1 The distance between the syringe needle and the collector is 15cm, and the rotation speed of the collector is set to 600rpm.
[0042] The ambient temperature in step four is room temperature, and the humidity is 30%.
[0043] The material used in step four needs to be dried in a vacuum drying oven at 60°C for 12h.
[0044] After drying the nanofiber in step four, it is calcined in a muffle furnace at 650°C for 2h to obtain the product.
[0045] The xWO3@SiO2 nanofiber in step five is added at 3wt.%, 5wt.%, 7wt.% or 10wt.%.
[0046] In step six, it is cast on a polytetrafluoroethylene substrate.
[0047] The thickness scraped in step six is 500μm.
[0048] The drying in step six needs to be dried in a vacuum oven at 80°C for 24h.
[0049] After drying and peeling in step six, it needs to be transferred to a vacuum drying oven for standby.
[0050] A metal oxide modified fiber material, comprising a carrier and a core, the core being tungsten oxide metal particles for promoting lithium salt dissociation, the carrier being silica nanofibers.
[0051] A metal oxide modified fiber material is prepared by the preparation method of the metal oxide modified fiber material as described above.
[0052] Application of a metal oxide modified fiber material as an electrolyte of a battery.
[0053] Example 1
[0054] Under a magnetic stirrer at room temperature, 2.6 g of tetraethyl orthosilicate, 0.75 g of ethanol, and 0.5 g of hydrochloric acid were stirred and homogenized to obtain solution A; 10 wt% of polyvinylpyrrolidone in solution B was dissolved in N,N-dimethylformamide and dimethyl sulfoxide to obtain solution B; solutions A and B were mixed and stirred to form a spinning solution; electrospinning was performed at room temperature with an applied voltage of 15 kV, a feeding rate controlled at 0.6 mL h -1 , a distance of 15 cm between the syringe needle and the collector, and a rotational speed of the collector set to 600 rpm; the nanofibers were continuously dried in a vacuum drying oven at 60°C for 12 h, and then calcined in a muffle furnace at 650°C for 2 h to obtain 0WO3@SiO2.
[0055] Example 2
[0056] Under a magnetic stirrer at room temperature, 2.6 g of tetraethyl orthosilicate, 0.75 g of ethanol, and 0.5 g of hydrochloric acid were stirred and homogenized to obtain solution A; 10 wt% of polyvinylpyrrolidone in solution B was dissolved in N,N-dimethylformamide and dimethyl sulfoxide to obtain solution B; solutions A and B were mixed and stirred to form a spinning solution; electrospinning was performed at room temperature with an applied voltage of 15 kV, a feeding rate controlled at 0.6 mL h -1 , a distance of 15 cm between the syringe needle and the collector, and a rotational speed of the collector set to 600 rpm; the nanofibers were continuously dried in a vacuum drying oven at 60°C for 12 h, and then calcined in a muffle furnace at 650°C for 2 h to obtain 3WO3@SiO2.
[0057] Example 3
[0058] Under a magnetic stirrer at room temperature, 2.6 g of tetraethyl orthosilicate, 0.75 g of ethanol, and 0.5 g of hydrochloric acid were stirred and homogenized to obtain solution A; 10 wt% of polyvinylpyrrolidone in solution B was dissolved in N,N-dimethylformamide and dimethyl sulfoxide to obtain solution B; solutions A and B were mixed and stirred to form a spinning solution; electrospinning was performed at room temperature with an applied voltage of 15 kV, a feeding rate controlled at 0.6 mL h-1 The distance between the syringe needle and the collector was 15 cm, and the rotation speed of the collector was set to 600 rpm. The nanofiber was continuously dried in a vacuum drying oven at 60 °C for 12 h, and then calcined in a muffle furnace at 650 °C for 2 h to obtain 5WO3@SiO2.
[0059] Example 4
[0060] At room temperature, 2.6 g of tetraethyl orthosilicate, 0.75 g of ethanol, and 0.5 g of hydrochloric acid and 0.7 g of tungsten chloride were stirred and homogenized to obtain solution A; 10 wt% of polyvinylpyrrolidone in solution B was dissolved in N,N-dimethylformamide and dimethyl sulfoxide to obtain solution B; A and B solutions were mixed and stirred to form a spinning solution; electrospinning was performed at room temperature with an applied voltage of 15 kV, and the feeding rate was controlled at 0.6 mL h -1 The distance between the syringe needle and the collector was 15 cm, and the rotation speed of the collector was set to 600 rpm. The nanofiber was continuously dried in a vacuum drying oven at 60 °C for 12 h, and then calcined in a muffle furnace at 650 °C for 2 h to obtain 7WO3@SiO2.
[0061] Example 5
[0062] Polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and lithium bisfluorosulfonylimide salt (LiFSI) were dissolved in N-methylpyrrolidone to form a homogeneous solution; the solution was poured onto a polytetrafluoroethylene substrate, and a 500-μm-thick film was obtained by scraping with a doctor blade. The film was dried in a vacuum oven at 80 °C for 24 h to obtain PL.
[0063] Example 6
[0064] Polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and lithium bisfluorosulfonylimide salt (LiFSI) were dissolved in N-methylpyrrolidone to form a homogeneous solution, and 3 wt.% of 5WO3@SiO2nanofiber prepared in Example 3 was added to form a mixed solution; the solution was poured onto a polytetrafluoroethylene substrate, and a 500-μm-thick film was obtained by scraping with a doctor blade. The film was dried in a vacuum oven at 80 °C for 24 h to obtain PL-5WO3-3@SiO2.
[0065] Example 7
[0066] Polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and lithium bisfluorosulfonylimide salt (LiFSI) were dissolved in N-methylpyrrolidone to form a homogeneous solution, and 5 wt.% of 5WO3@SiO2nanofiber prepared in Example 3 was added to form a mixed solution; the solution was poured onto a polytetrafluoroethylene substrate, and a 500-μm-thick film was obtained by scraping with a doctor blade. The film was dried in a vacuum oven at 80 °C for 24 h to obtain PL-5WO3-5@SiO2.
[0067] Example 8
[0068] Polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and lithium bisfluorosulfonylimide (LiFSI) were dissolved in N-methyl pyrrolidone to form a homogeneous solution, 7wt.% of 5WO3@SiO2 nanofibers described in Example 3 were added, and a mixed solution was formed by magnetic stirring; the solution was poured onto a polytetrafluoroethylene substrate, a 500 μm film was obtained by scraping, and the film was dried in a vacuum oven at 80°C for 24h to obtain PL-5WO3-7@SiO2.
[0069] Example 9
[0070] Polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and lithium bisfluorosulfonylimide (LiFSI) were dissolved in N-methyl pyrrolidone to form a homogeneous solution, 10wt.% of 5WO3@SiO2 nanofibers described in Example 3 were added, and a mixed solution was formed by magnetic stirring; the solution was poured onto a polytetrafluoroethylene substrate, a 500 μm film was obtained by scraping, and the film was dried in a vacuum oven at 80°C for 24h to obtain PL-5WO3-10@SiO2.
[0071] The samples obtained in Examples 1-4 were subjected to X-ray diffraction testing, and the test results are shown in Figure 1 From the XRD patterns, the diffraction peaks of tungsten oxide were shown, and as the content of tungsten chloride was added, the metal loading was increased, and the characteristic peaks of tungsten oxide were enhanced in the patterns, and the crystallinity was enhanced.
[0072] The samples obtained in Examples 2-4 were scanned by scanning electron microscopy, and the test results are shown in Figure 2 From Figure 2 , it can be seen that when the content of tungsten chloride is less than or equal to 0.5g, the content in the solution is low, which is beneficial to dispersion in the polymer, and the obtained fiber is smoother; and when the content of tungsten chloride is 0.7g, the content in the solution is high, which is not conducive to dispersion, leading to the precipitation of fibers on the surface and the formation of small particles, affecting the morphology of the fibers.
[0073] The samples obtained in Examples 6-9 were scanned by scanning electron microscopy, and the test results are shown in Figure 3 From Figure 3 , it can be seen that when the content of 5WO3@SiO2 is 3wt.%, the cross-section structure shows a loose feature with obvious voids, and when the content is 7wt.% and 10wt.%, the cross-section shows a concave-convex phenomenon, indicating that the content of inorganic filler is too high, and when the content is 5wt.%, the appearance is uniform and smooth.
[0074] Example 7 was compared with Example 5, and the test result graph is shown in Figure 4The results show that the tensile strain and ultimate tensile strength of the material of Example 7 are improved, which is due to the introduction of inorganic fillers to enhance the interface bonding strength of the polymer body.
[0075] Example 7 and Example 5 were subjected to symmetric battery constant current cycle stability test, and the test results are shown in the following figures Figure 5 The results show that the Li||Example 7||Li battery exhibits point fluctuation after 800h of cycle stability under the constant current density of 0.2mA cm -2 , while the Li||Example 5||Li battery exhibits a sharp rise in overpotential after 178h of cycle stability.
[0076] Example 7 and Example 5 were subjected to 30 cycles and then scanned by scanning electron microscope, and the test results are shown in the following figures Figure 6 The results show that the lithium metal surface after cycle using the sample of Example 7 still maintains flat,
[0077] while the lithium metal surface of Example 5 exhibits irregular protruding surface. The difference is due to the higher ionic conductivity of Example 7, which has a longer service life.
[0078] In summary, the present application provides a preparation method and application of a silicon-based fiber material loaded with tungsten oxide and a polyvinylidene-hexafluoropropylene copolymer-based composite electrolyte. The silicon-based fiber material loaded with tungsten oxide can be used to improve the performance of the battery. The main advantage is that tungsten oxide can adjust the lithium ion deposition behavior, suppress the local current density, improve the interface stability, and prolong the cycle life of the battery. The solid-state electrolyte produced under this condition has a performance far superior to that of the polyvinylidene-hexafluoropropylene copolymer-based electrolyte and exhibits long-term stability. Therefore, the present application not only improves the defects of the prior art, but also has significant industrial application value.
[0079] The embodiments described with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be understood as limiting the present application. The embodiments should not be considered as limiting the present application, but any improvement made on the basis of the spirit of the present application should be within the scope of protection of the present application.
Claims
1. A method for the preparation of a metal oxide modified fibrous material, characterized by: comprising the steps of Step one, stirring tetraethyl orthosilicate, ethanol, hydrochloric acid and tungsten chloride until the solute is completely dissolved to form a mixture A; Step two, dissolving polyvinylpyrrolidone in N,N-dimethylformamide and dimethyl sulfoxide to obtain a mixture B; Step three, stirring the mixture of step one and step two; Step four, electrospinning the mixed solution of step three to form xWO3@SiO2 nanofibers; Step five, dissolving polyvinylidene fluoride-hexafluoropropylene copolymer and lithium bisfluorosulfonylimide salt in N-methylpyrrolidone to form a homogeneous solution, adding xWO3@SiO2 nanofibers of step four; Step six, after magnetic stirring to form a mixed suspension, pouring into a mold, scraping with a doctor blade to a certain thickness, and drying.
2. A method of preparing a metal oxide modified fibrous material according to claim 1, characterized in that: The tetraethyl orthosilicate: ethanol: hydrochloric acid: tungsten chloride in step one is 2.6g: 0.75g: 0.5g: x g, where x = 0.3, 0.5 or 0.
7.
3. A method of preparing a metal oxide modified fibrous material according to claim 1, characterized in that: The polyvinylpyrrolidone in step two accounts for 10wt% of the mixed solution.
4. A method of preparing a metal oxide modified fibrous material according to claim 1, characterized in that: The electrospinning voltage in step four was 15 kV, and the feed rate was controlled at 0.6 mL h -1 The distance between the syringe needle and the collector was 15 cm, and the rotation speed of the collector was set at 600 rpm.
5. A method of preparing a metal oxide modified fibrous material according to claim 1, characterized in that: The nanofibers in step four are dried and calcined in a muffle furnace at 650℃ for 2h to obtain the product.
6. A method of preparing a metal oxide modified fibrous material according to claim 1, characterized in that: The xWO3@SiO2 nanofibers in step five are added at 3wt.%, 5wt.%, 7wt.% or 10wt.%.
7. A method of preparing a metal oxide modified fibrous material according to any one of claims 1 to 6, characterised in that: In step six, pouring on a polytetrafluoroethylene substrate.
8. A metal oxide modified fibrous material, characterized by, comprising a carrier and a core, the core being tungsten oxide metal particles for promoting lithium salt dissociation, and the carrier being silica nanofibers.
9. A metal oxide modified fibrous material according to claim 8, wherein, Prepared by the method of any one of claims 1-6.
10. Use of the metal oxide modified fibrous material of any one of claims 8-9 as an electrolyte for a battery.